How old should your boiler be before you replace it?

A home energy expert, from not-for-profit energy group Ebico, replies: With
winter upon us, keeping our homes warm is crucial. And with energy
prices remaining high, it’s now more important than ever to think about
the efficiency of your central heating boiler to ensure you’re not
paying more than you have to on your energy bills.

The heat is on: If your boiler is more than 20 years old you could save money by replacing it with a condensing boiler.

If you heat your home with a boiler and radiators, it is likely that roughly two-thirds of your total home energy expenditure goes on the fuel, (whether that be mains gas, oil or LPG,) used to run your central heating.

The proportion of energy inherent in the fuel that is used to run the boiler, and ultimately converted into heat, establishes the efficiency of the boiler. To put it another way, the higher your boiler’s efficiency, the less amount of fuel needed to create the same amount of heat in your home.

A step-change in boiler efficiency took place back in the 1980s, when 'condensing' boilers were first introduced to the market.

A high efficiency condensing boiler is widely regarded as a good choice if you're looking for an environmentally friendly and more efficient boiler, as they are able to make better use of the heat they generate from burning fuels, such as gas or oil.

With a heat only boiler, some heat is wasted with hot gases released from the flue.

However, a condensing boiler captures some of the heat from these waste gases and uses it to heat water returning from your central heating system. As a result, it requires less heat from the burner and is consequently much more efficient.

A modern condensing boiler will have an efficiency of around 90 per cent, whereas a non-condensing boiler – even a new one – will only offer about 75 per cent. In a typical semi-detached house, this difference could mean a saving of around £150 per year.

Because of early reliability issues, condensing boilers did not come into widespread use until the 1990s. Therefore, any central heating system using a boiler that is more than 20 years old is likely to be made significantly cheaper to run by replacing with a condensing boiler.

As boilers age – particularly those that are not well maintained – they become less efficient. This combination of age and old technology means that an older boiler is likely to have significantly higher annual running costs, compared with a modern replacement – as much as £300 per year in a typical semi-detached home.

However, even at this level of excess expenditure, it would take around 6 years to recover the cost of installing a new boiler (roughly £2,000), so other factors will play a crucial role in your decision making process.

When deciding on whether to switch to a more energy efficient boiler, ask yourself the following questions:

• Is the boiler so old that maintenance is becoming very expensive or parts unavailable?• Is the floor-space the old boiler is occupying needed for something else (modern domestic boilers are wall-mounted)? • Are grants available to reduce the boiler’s effective purchase cost? (As is the case in Scotland. See www.scotland.gov.uk for more information.)

The efficiencies of most common boilers can be found atwww.sedbuk.com.

Home Energy Expert is a free energy advice service from Ebico, the UK’s only not-for-profit energy company and National Energy Action, the UK’s leading fuel poverty charity, committed to improving the quality of life of low income households and campaigning for warm homes.

Home Energy Expert has teamed up with This is Money to answer any burning questions about energy in your home. If you want to improve your energy efficiency and save money then email your question with Home Energy Expert in the subject line to: editor@thisismoney.co.ukFor more information click on to: www.ebico.org.uk